Affinage

NEK8

Serine/threonine-protein kinase Nek8 · UniProt Q86SG6

Length
692 aa
Mass
74.8 kDa
Annotated
2026-04-29
32 papers in source corpus 20 papers cited in narrative 21 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NEK8 is a serine/threonine kinase that operates at the intersection of primary cilium signaling, Hippo pathway regulation, and replication stress suppression. It localizes to the proximal 'Inv compartment' of primary cilia via its RCC1 domain, where it is anchored by Inversin and activated by ANKS6 binding to its kinase domain, and it phosphorylates polycystin-2 to regulate ciliary mechanosensory signaling and left-right patterning (PMID:25599650, PMID:23274954, PMID:18235101). NEK8 suppresses replication stress-induced DNA double-strand breaks by limiting cyclin A–CDK activity and promoting RAD51-dependent replication fork protection, with both loss and overexpression of NEK8 impairing homologous recombination (PMID:23973373, PMID:27892797, PMID:41101173). Heterozygous kinase-domain variants in NEK8 cause autosomal dominant polycystic kidney disease through a dominant-negative mechanism that reduces polycystin-2 ciliary localization and increases DNA damage (PMID:37598857).

Mechanistic history

Synthesis pass · year-by-year structured walk · 12 steps
  1. 2002 High

    Identification of NEK8 as an active kinase with a defined domain architecture and its first substrate (BICD2) established NEK8 as a catalytically competent member of the NEK family capable of autophosphorylation and oligomerization.

    Evidence Biochemical purification of beta-casein kinase activity, in vitro kinase assay, co-immunoprecipitation for BICD2 association

    PMID:11864968

    Open questions at the time
    • Physiological relevance of BICD2 phosphorylation undefined
    • No in vivo kinase substrates confirmed at this stage
  2. 2008 High

    Determining that NEK8 localizes to the proximal primary cilium and that disease-associated RCC1-domain mutations disrupt this localization linked NEK8 to ciliopathy pathogenesis and defined the RCC1 domain as essential for ciliary targeting.

    Evidence GFP-tagged constructs in IMCD-3 cells with immunofluorescence; multiple disease mutations analyzed

    PMID:18189147 PMID:18199800

    Open questions at the time
    • Mechanism by which RCC1 domain mediates ciliary targeting not resolved
    • Kinase domain contribution to localization only partially characterized
  3. 2008 High

    Discovery that NEK8 interacts with and regulates the phosphorylation and ciliary trafficking of polycystin-2 connected NEK8 kinase function to PKD-relevant ciliary signaling.

    Evidence Co-immunoprecipitation of NEK8 and PC2; altered PC2 phosphorylation and ciliary accumulation in jck mouse kidneys

    PMID:18235101

    Open questions at the time
    • Whether NEK8 directly phosphorylates PC2 or acts indirectly was unresolved
    • Specific phosphorylation sites on PC2 not mapped
  4. 2010 High

    Epistasis analysis established that Inversin anchors NEK8 (and NPHP3) within the proximal ciliary Inv compartment, defining a hierarchical localization module for nephronophthisis-associated proteins.

    Evidence Immunofluorescence in inv-mutant and wild-type mouse cells with epistatic localization comparisons

    PMID:20169535

    Open questions at the time
    • Direct physical interaction between Inversin and NEK8 not biochemically demonstrated in this study
    • How the Inv compartment boundary is established remains unknown
  5. 2011 High

    Demonstration that autophosphorylation within the catalytic domain promotes centrosomal recruitment and that ciliogenesis triggers both NEK8 activation and its proteasomal degradation revealed a feedback mechanism coupling kinase activation to protein turnover.

    Evidence In vitro kinase assays with domain mutants, proteasome inhibitor treatment, immunofluorescence

    PMID:22106379

    Open questions at the time
    • Specific autophosphorylation sites not mapped
    • Identity of E3 ligase mediating NEK8 degradation unknown at this stage
  6. 2012 High

    Phenocopying of Pkd2-null defects by Nek8-null mice and demonstration that NEK8 is required for fluid shear stress responses placed NEK8 functionally upstream of polycystin-2-dependent mechanosensory signaling and left-right asymmetry.

    Evidence Nek8-null mouse model, zebrafish morpholino, fluid shear stress assays in IMCD cells

    PMID:23274954

    Open questions at the time
    • Precise molecular step at which NEK8 acts on the PC2 signaling cascade not defined
    • Whether NEK8 kinase activity is required for shear stress response not tested
  7. 2012 High

    Discovery that NEK8 directly binds TAZ, promotes its nuclear translocation by competing with 14-3-3 cytoplasmic retention, and drives TAZ-dependent proliferation linked NEK8 to Hippo pathway regulation beyond ciliary signaling.

    Evidence Co-immunoprecipitation, nuclear/cytoplasmic fractionation, siRNA knockdown, proliferation assays

    PMID:23026745

    Open questions at the time
    • Whether NEK8 phosphorylates TAZ directly was not shown
    • Relationship between ciliary and nuclear TAZ functions of NEK8 unclear
  8. 2013 High

    Three parallel advances defined NEK8's roles in DNA replication stress, the ANKS6-containing ciliary complex, and YAP/TAZ co-regulation with NPHP3: NEK8 suppresses DSBs by limiting cyclin A–CDK activity, ANKS6 connects NEK8 to the Inv/NPHP3 ciliary module, and NEK8 cooperates with NPHP3 to activate TAZ.

    Evidence DNA fiber analysis, CDK activity assays, γH2AX immunofluorescence, mouse kidney analysis (PMID:23973373); co-IP and zebrafish/Xenopus knockdown for ANKS6 complex (PMID:23793029); co-IP in patient fibroblasts (PMID:23418306)

    PMID:23418306 PMID:23793029 PMID:23973373

    Open questions at the time
    • How NEK8 limits cyclin A–CDK activity mechanistically undefined
    • Whether ANKS6 hydroxylation by HIF1AN alters NEK8 activation specifically not tested
    • Direct kinase-substrate relationship between NEK8 and CDK substrates not established
  9. 2015 High

    Reconstitution of ANKS6 as a direct activator of NEK8 kinase activity — binding to the kinase domain and requiring the interaction for Inv-compartment function — resolved how NEK8 is switched on in the cilium.

    Evidence In vitro kinase assay showing ANKS6-dependent activation, Anks6-Streaker and Nek8-Roc mouse mutants with reciprocal epistasis

    PMID:25599650

    Open questions at the time
    • Structural basis for ANKS6-mediated kinase activation unknown
    • Whether other activators exist besides ANKS6 not explored
  10. 2016 High

    Extension of NEK8's Hippo pathway role to YAP and demonstration that pharmacological YAP inhibition partially rescues Nek8-null 3D spheroid defects suggested YAP dysregulation as a therapeutic target in NEK8-associated cystic disease; simultaneously, NEK8 was shown to promote RAD51 focus formation and protect stalled replication forks.

    Evidence Patient fibroblasts, 3D spheroids, zebrafish, Verteporfin rescue (PMID:26967905); siRNA screen, Nek8-KO MEFs, DNA fiber analysis, RAD51 fractionation (PMID:27892797)

    PMID:26967905 PMID:27892797

    Open questions at the time
    • Whether YAP dysregulation is cause or consequence of cystogenesis not fully resolved
    • Mechanism by which NEK8 promotes RAD51 loading not identified
  11. 2023 High

    Identification of c-MYC Ser405 as a direct NEK8 phosphorylation site that stabilizes MYC via polyubiquitination, and of dominant-negative NEK8 kinase-domain variants causing autosomal dominant PKD, expanded the substrate repertoire and disease spectrum of NEK8.

    Evidence In vitro kinase assay with mutagenesis for MYC (PMID:37596667); patient variant reconstitution in Nek8-KO IMCD3 cells with PC2 and DNA damage readouts (PMID:37598857)

    PMID:37596667 PMID:37598857

    Open questions at the time
    • In vivo relevance of MYC Ser405 phosphorylation to cystic disease not demonstrated
    • Dominant-negative mechanism of heterozygous variants not structurally explained
  12. 2025 Medium

    NEK8 was found to phosphorylate ASNS (stabilizing it to activate mTORC1) and LDHA (driving lactate overproduction and immune evasion), while USP51 was identified as a deubiquitinase stabilizing NEK8 itself — broadening NEK8's role to metabolic reprogramming and immune regulation in cancer.

    Evidence In vitro kinase assays with mutagenesis for ASNS (PMID:39762761) and LDHA (PMID:41904143); co-IP and ubiquitination assay for USP51–NEK8 (PMID:41475333); overexpression studies linking NEK8 to HR impairment and PARP inhibitor sensitivity (PMID:41101173)

    PMID:39762761 PMID:41101173 PMID:41475333 PMID:41904143

    Open questions at the time
    • Cancer-context substrates (ASNS, LDHA, MYC) not validated in ciliary/renal settings
    • Whether USP51 regulates NEK8 in ciliated epithelial cells unknown
    • Dosage-dependent effects (loss vs. overexpression) on HR need mechanistic reconciliation

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include the structural basis for ANKS6-mediated NEK8 activation, the mechanism by which NEK8 limits cyclin A–CDK activity, how NEK8's ciliary and nuclear/replication stress functions are coordinated, and whether cancer-context substrates are relevant to its physiological ciliary role.
  • No crystal structure of NEK8 kinase domain or ANKS6 complex available
  • Mechanism connecting NEK8 to cyclin A–CDK suppression remains uncharacterized
  • Integration of ciliary, Hippo, and DNA damage functions into a unified model is lacking

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140096 catalytic activity, acting on a protein 7 GO:0016740 transferase activity 6
Localization
GO:0005929 cilium 6 GO:0005815 microtubule organizing center 2 GO:0005634 nucleus 1
Pathway
R-HSA-162582 Signal Transduction 4 R-HSA-1643685 Disease 4 R-HSA-1852241 Organelle biogenesis and maintenance 4 R-HSA-73894 DNA Repair 3 R-HSA-69306 DNA Replication 2 R-HSA-1640170 Cell Cycle 1
Partners
ANKS6BICD2INVSMYCNPHP3PKD2TAZUSP51
Complex memberships
Inversin compartment complex (INVS/NPHP3/NEK8/ANKS6)

Evidence

Reading pass · 21 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2002 NEK8 was isolated as a beta-casein kinase activity, demonstrated to autophosphorylate, oligomerize, and phosphorylate BICD2 (Bicaudal D2) in vitro; endogenous NEK8 and BICD2 associate in vivo, and NEK8 contains an N-terminal kinase domain, central RCC1-homology domain, and C-terminal coiled-coil domain. Biochemical purification, in vitro kinase assay, co-immunoprecipitation, cell fractionation The Journal of biological chemistry High 11864968
2008 NEK8 localizes to the proximal portion of primary cilia and to centrosomes; disease-associated mutations in the RCC1 domain (H425Y, L330F, A497P) disrupt ciliary and/or centrosomal localization without affecting ciliogenesis or centriole number. GFP-tagged construct overexpression in IMCD-3 cells, immunofluorescence microscopy Journal of the American Society of Nephrology : JASN High 18199800
2008 NEK8 interacts with polycystin-2 (PC2) by co-immunoprecipitation; the jck mutation causes abnormal phosphorylation of PC2, ciliary elongation, and ciliary accumulation of PC1 and PC2, indicating NEK8 regulates polycystin trafficking and phosphorylation. Co-immunoprecipitation, Western blot, real-time RT-PCR, immunofluorescence in jck mouse kidneys Journal of the American Society of Nephrology : JASN High 18235101
2008 Both the kinase domain and the C-terminal RCC1 domain of NEK8 are required for correct ciliary targeting; kinase-deficient and jck mutant forms of NEK8 fail to target to cilia, but do not affect ciliogenesis or ciliary length. GFP-tagged construct transfection, immunofluorescence in kidney epithelial cells Pediatric nephrology (Berlin, Germany) Medium 18189147
2010 Inversin (Inv/NPHP2) acts as a molecular anchor for NPHP3 and NEK8 in the 'Inv compartment' (proximal ciliary segment); loss of Inv disrupts NEK8 and NPHP3 compartmental localization, while loss of NEK8 or NPHP3 does not affect Inv localization. Immunofluorescence in inv mutant and wild-type mouse cells; epistatic localization analysis Cytoskeleton (Hoboken, N.J.) High 20169535
2011 NEK8 kinase activity is required for centrosome/ciliary localization; the RCC1 domain alone localizes correctly and can be phosphorylated by the NEK8 kinase domain; autophosphorylation within the catalytic domain promotes centrosome recruitment via a conformational change; ciliogenesis triggers both activation and proteasomal degradation of NEK8. In vitro kinase assays, domain deletion/mutation constructs, proteasome inhibitor treatment, immunofluorescence Human molecular genetics High 22106379
2012 NEK8 interacts with polycystin-2 (PC2); Nek8-null mice and Pkd2-null mice share strikingly similar embryonic phenotypes (left-right randomization, cardiac anomalies); NEK8-depleted IMCD cells show defective response to fluid shear stress similar to PC2-deficient cells, placing NEK8 upstream of PC2-dependent mechanosensory signaling. Co-immunoprecipitation, Nek8-null mouse generation, zebrafish morpholino knockdown, fluid shear stress assay in IMCD cells Journal of the American Society of Nephrology : JASN High 23274954
2012 NEK8 (NPHP9) directly interacts with TAZ and induces nuclear translocation of TAZ; 14-3-3 competes with NEK8 for TAZ binding (14-3-3 favoring cytoplasmic retention vs. NEK8 mediating nuclear delivery); NEK8 knockdown inhibits TAZ-dependent cell proliferation. Co-immunoprecipitation, nuclear/cytoplasmic fractionation, siRNA knockdown, proliferation assays Human molecular genetics High 23026745
2013 ANKS6 localizes to the proximal cilium (Inv compartment) and connects NEK8 to INVS and NPHP3 within a nephronophthisis module; HIF1AN hydroxylates both ANKS6 and INVS and alters the composition of the ANKS6-INVS-NPHP3 complex. Co-immunoprecipitation, zebrafish/Xenopus knockdown, immunofluorescence, network analyses, hydroxylation assay Nature genetics High 23793029
2013 NEK8 is required for ATR-mediated replication stress response; NEK8-deficient cells form spontaneous DNA double-strand breaks, show reduced replication fork rates, unscheduled origin firing, and fork collapse; NEK8 suppresses DSBs by limiting cyclin A-associated CDK activity; kidneys of NEK8-mutant mice accumulate DNA damage. siRNA/shRNA knockdown, DNA fiber analysis, EdU incorporation, DSB immunofluorescence (γH2AX), CDK activity assays, 3D renal cell culture, mouse kidney analysis Molecular cell High 23973373
2013 NEK8 and NPHP3 interact and together activate the Hippo effector TAZ; complete loss of NEK8 leads to decreased PKD1/PKD2 expression and upregulation of c-MYC. Co-immunoprecipitation, Western blot in patient-derived fibroblasts, immunofluorescence Human molecular genetics Medium 23418306
2015 ANKS6 is a direct activator of NEK8 kinase: ANKS6 binds to the NEK8 kinase domain and activates its kinase activity; ANKS6 requires NEK8 for its localization to the ciliary Inv compartment; the Anks6(Streaker) mutation decreases ANKS6–NEK8 interaction, preventing NEK8 activation, while the Nek8(Roc) mutation inactivates kinase function while preserving ANKS6 localization. In vitro kinase assay, co-immunoprecipitation, mouse mutant analysis (Anks6-Streaker and Nek8-Roc alleles), immunofluorescence Nature communications High 25599650
2016 NEK8 regulates the Hippo pathway effector YAP; NEK8 loss-of-function and missense mutations differentially alter YAP activity and target gene expression in patient fibroblasts and renal cells; YAP imbalance is observed in Nek8-null 3D spheroids and jck mouse cystic kidneys; YAP inhibitor Verteporfin partially rescues Nek8-null 3D spheroid defects. Patient fibroblast analysis, mIMCD3 cell studies, 3D spheroid culture, zebrafish co-injection, Verteporfin treatment, Western blot for YAP targets PLoS genetics High 26967905
2016 NEK8 is required for efficient DNA damage-induced RAD51 focus formation and replication fork protection; NEK8-depleted and Nek8-knockout cells show decreased RAD51 chromatin loading and degradation of nascent DNA at stalled forks; NEK8-null cells are sensitive to hydroxyurea and ATR inhibition. siRNA screen, Nek8 knockout MEFs, DNA fiber analysis, RAD51 chromatin fractionation, immunofluorescence Cell cycle (Georgetown, Tex.) High 27892797
2023 NEK8 phosphorylates c-MYC at serine 405, which enhances MYC stability via polyubiquitination (rather than degradation) in colorectal cancer cells. In vitro kinase assay, phosphorylation site mutagenesis, ubiquitination assay, Western blot, co-immunoprecipitation Cell communication and signaling : CCS Medium 37596667
2023 Heterozygous NEK8 kinase-domain variants (p.Arg45Trp, p.Lys157Gln) reduce kinase activity in vitro, decrease polycystin-2 (PC2) ciliary localization, and increase DNA damage signaling, acting via a dominant-negative mechanism to cause autosomal dominant PKD. In vitro kinase assay, Nek8-knockout IMCD3 reconstitution, immunofluorescence for ciliary PC2/ANKS6, DNA damage markers in patient tubuloids and IMCD3 cells Kidney international High 37598857
2025 NEK8 directly phosphorylates asparagine synthetase (ASNS) at serine 349, inhibiting ASNS ubiquitination and degradation; this stabilizes ASNS and promotes asparagine synthesis to activate the mTORC1 pathway in gastric cancer cells. Co-immunoprecipitation, in vitro phosphorylation assay, ubiquitination assay, alanine substitution mutagenesis, mTORC1 activity readout Molecular medicine (Cambridge, Mass.) Medium 39762761
2025 USP51 deubiquitinase directly interacts with NEK8 and reduces NEK8 ubiquitination, thereby stabilizing NEK8 protein; NEK8 in turn modulates the WNT/β-catenin pathway in colorectal cancer cells. Co-immunoprecipitation, co-immunofluorescence, ubiquitination assay, knockdown functional rescue, Western blot for β-catenin Pathology, research and practice Medium 41475333
2025 NEK8 overexpression inhibits RAD51 focus formation, impairs homologous recombination, causes degradation of stalled replication forks, and sensitizes cells to PARP inhibitor Olaparib. NEK8 overexpression in cell lines, RAD51 foci immunofluorescence, DNA fiber analysis, Olaparib sensitivity assay DNA repair Medium 41101173
2026 NEK8 phosphorylates lactate dehydrogenase A (LDHA), driving lactate overproduction; elevated lactate promotes histone modifications silencing antigen presentation machinery and impairs CD8+ T cell function in colorectal cancer; NEK8 inhibition (CX6258) restores CD8+ T cell infiltration. In vitro kinase assay for LDHA phosphorylation, metabolic profiling, histone modification analysis, immune cell functional assays, pharmacological inhibition Nature communications Medium 41904143
2024 In C. elegans, the Inversin complex (containing NEKL-2/NEK8, MLT-4/INVS) is activated by dimerization; stimulated dimerization of NEKL-2 via optogenetics is sufficient to recapitulate constitutively active complex phenotypes and can bypass a lethal MLT-4 mutant, demonstrating dimerization is required for functional activation. C. elegans genome engineering (RFP tagging), optogenetic dimerization, genetic epistasis, monomerization suppression assay bioRxivpreprint Medium

Source papers

Stage 0 corpus · 32 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2013 ANKS6 is a central component of a nephronophthisis module linking NEK8 to INVS and NPHP3. Nature genetics 170 23793029
2008 NEK8 mutations affect ciliary and centrosomal localization and may cause nephronophthisis. Journal of the American Society of Nephrology : JASN 168 18199800
2013 NEK8 links the ATR-regulated replication stress response and S phase CDK activity to renal ciliopathies. Molecular cell 117 23973373
2008 Nek8 regulates the expression and localization of polycystin-1 and polycystin-2. Journal of the American Society of Nephrology : JASN 95 18235101
2004 Nek8, a NIMA family kinase member, is overexpressed in primary human breast tumors. Gene 86 15019993
2013 Mutations in NEK8 link multiple organ dysplasia with altered Hippo signalling and increased c-MYC expression. Human molecular genetics 82 23418306
2010 Inv acts as a molecular anchor for Nphp3 and Nek8 in the proximal segment of primary cilia. Cytoskeleton (Hoboken, N.J.) 81 20169535
2016 Novel NEK8 Mutations Cause Severe Syndromic Renal Cystic Dysplasia through YAP Dysregulation. PLoS genetics 76 26967905
2012 The ciliopathy disease protein NPHP9 promotes nuclear delivery and activation of the oncogenic transcriptional regulator TAZ. Human molecular genetics 67 23026745
2011 The Nek8 protein kinase, mutated in the human cystic kidney disease nephronophthisis, is both activated and degraded during ciliogenesis. Human molecular genetics 60 22106379
2012 A novel mutation causing nephronophthisis in the Lewis polycystic kidney rat localises to a conserved RCC1 domain in Nek8. BMC genomics 57 22899815
2013 Loss of the ciliary kinase Nek8 causes left-right asymmetry defects. Journal of the American Society of Nephrology : JASN 52 23274954
2002 Purification, cloning, and characterization of Nek8, a novel NIMA-related kinase, and its candidate substrate Bicd2. The Journal of biological chemistry 51 11864968
2015 ANKS6 is the critical activator of NEK8 kinase in embryonic situs determination and organ patterning. Nature communications 47 25599650
2005 Nek8 mutation causes overexpression of galectin-1, sorcin, and vimentin and accumulation of the major urinary protein in renal cysts of jck mice. Molecular & cellular proteomics : MCP 43 15872312
2007 Pkd1 and Nek8 mutations affect cell-cell adhesion and cilia in cysts formed in kidney organ cultures. American journal of physiology. Renal physiology 41 17928412
2023 Certain heterozygous variants in the kinase domain of the serine/threonine kinase NEK8 can cause an autosomal dominant form of polycystic kidney disease. Kidney international 34 37598857
2008 Defects in ciliary localization of Nek8 is associated with cystogenesis. Pediatric nephrology (Berlin, Germany) 30 18189147
2016 NEK8 regulates DNA damage-induced RAD51 foci formation and replication fork protection. Cell cycle (Georgetown, Tex.) 23 27892797
2013 Nek8 couples renal ciliopathies to DNA damage and checkpoint control. Molecular cell 22 23973371
2012 The ciliary protein Nek8/Nphp9 acts downstream of Inv/Nphp2 during pronephros morphogenesis and left-right establishment in zebrafish. FEBS letters 19 22687244
2015 Compound heterozygous mutations in NEK8 in siblings with end-stage renal disease with hepatic and cardiac anomalies. American journal of medical genetics. Part A 18 26697755
2023 NEK8 regulates colorectal cancer progression via phosphorylating MYC. Cell communication and signaling : CCS 12 37596667
2025 NEK8 promotes the progression of gastric cancer by reprogramming asparagine metabolism. Molecular medicine (Cambridge, Mass.) 7 39762761
2022 NEK8-Associated Nephropathies: Do Autosomal Dominant Forms Exist? Nephron 6 36215968
2025 NEK8, a NIMA-family protein kinase at the core of the ciliary INV complex. Cell communication and signaling : CCS 4 40189576
2022 Never-in-Mitosis A-Related Kinase 8 (NEK8) Regulates Adipogenesis, Glucose Homeostasis, and Obesity. Oxidative medicine and cellular longevity 4 36506932
2026 Multi-omics profiling of sodium-overload (NECSO) programs identifies NEK8 as a central driver of colorectal cancer progression through single-cell and spatial transcriptomics. Frontiers in immunology 0 41743703
2026 NEK8 kinase-mediated lactate increase impairs antitumor immunity decreasing radiotherapy sensitivity in colorectal cancer. Nature communications 0 41904143
2025 Overexpression of the NEK8 kinase inhibits homologous recombination. bioRxiv : the preprint server for biology 0 39975112
2025 Overexpression of the NEK8 kinase inhibits homologous recombination. DNA repair 0 41101173
2025 NEK8 stabilization via USP51-mediated deubiquitination promotes colorectal cancer progression. Pathology, research and practice 0 41475333